Rope Stretch

[AJ]

Okay, I'll start by saying I read the various climbing magazines. I noticed something with the last issue of R+I and the Climbing that was just dropped off. Did the UIAA or some other body change the way rope stretch is measured? I thought it was a joke when I saw the BlueWater add (the annoying BW spiderman guy) and the claim of something like 35% rope stretch. I also saw that PMI is now quoting similar numbers, but they say something to the effect of 6% static method and 30+% "new method". Are they doing some kind of fast, "dynamic" test now? Is this a UIAA or Cordage Institute or other test?

[AJ]

I decided to do some checking on my own question. Apparently there is a new test for measuring rope stretch. According to Scott Newell at BlueWater the new method will probably displace the old one in a couple years. Basically the new test is more of a "dynamic" or rapid-load type of test. This should simulate the rope stretch experienced in a real fall more than the old method which used a "static" or very slow pull type of loading. In fact, if you look at PMI or Roca's rope stretch numbers they report both the old and new, but the new number says it is for a first fall on a rope. The amount of rope stretch decreases with each subsequent fall until the rope eventually loses its elasticity. I'll follow up if I get more information.